Electrical resistance heating units for various types of food-warming and heating or cooking have been known for many years. Usually these are referred to as electric hot plates. Typical examples of this type of device are illustrated respectively in the following U.S. Patents:
No. 1,990,640 Doherty Feb. 12, 1935 PA1 No. 2,253,927 Butler et al Aug. 26, 1941 PA1 No. 3,395,266 Price July 30, 1968 PA1 No. 3,725,641 Tilp Apr. 3, 1973 PA1 No. 3,876,861 Wightman et al Apr. 8, 1975
As far as is known, especially as illustrated by the foregoing patents, electrical heating devices of this type include heating units which are permanently affixed to the bases which support them, whereby unless the heating unit is appropriate sealed against the ingress of water or other cleaning fluid, it normally is not possible to cleanse the base simply by immersing the same in dishwater or the like, or mechanical dish washing equipment, due to the fact that the average type of electrical heating unit would be impaired by such cleansing operation. The present invention overcomes this difficulty by a structure which is described in the following specification and illustrated in the drawing comprising a part thereof.